Blackberry plant named &#39;A-2312&#39;

ABSTRACT

Description and specifications of a new and distinct blackberry cultivar named ‘A-2312’ which originated from seed produced by a hand pollinated cross of Ark. Selection APF-1 (non-patented, unreleased genotype)×A-2002 (non-patented, unreleased genotype) is provided. This new blackberry cultivar can be distinguished by its firm, large, sweet fruit with excellent postharvest handling potential, attractive fruit appearance, very good flavor, excellent plant health, potential reduced chilling requirement compared to other University of Arkansas&#39;s cultivars, and high yields.

LATIN NAME

Rubus subgenus Rubus Watson

BACKGROUND

The new cultivar of blackberry called ‘A-2312’ is described herein. Thenew cultivar originated from a hand-pollinated cross of Ark. SelectionAPF-1×A-2002 made in 2000. The seeds resulting from this controlledhybridization were germinated in a greenhouse in the spring of 2001 andplanted in a field near Clarksville, Ark. (West-Central Arkansas). Theseedlings fruited in the summer of 2002 and one seedling, designatedA-2312, was selected for its firm, large, sweet fruit with excellentpostharvest handling potential, attractive fruit appearance, very goodflavor, excellent plant health, potential reduced chilling requirementcompared to other University of Arkansas's cultivars, and high yields.

SUMMARY OF THE INVENTION

The new and distinct cultivar of blackberry originated from ahand-pollinated cross of Ark. Selection APF-1 (non-patented, unreleasedgenotype; female)×A-2002 (non-patented, unreleased genotype; male) madein 2000 and located near Clarksville, Ark. (West-Central Arkansas). Thebotanical designation of the new cultivar of blackberry is Rubussubgenus Rubus Watson.

The seeds resulting from this controlled hybridization were germinatedin a greenhouse in the spring of 2001 and planted in a field nearClarksville, Ark. The seedlings fruited in the summer of 2002 onfloricanes and one seedling, designated A-2312, was selected for itsfirm, large, sweet fruit with excellent postharvest handling potential,attractive fruit appearance, very good flavor, excellent plant health,potential reduced chilling requirement compared to other University ofArkansas's cultivars, and high yields.

During 2002, the original plant selection was propagated asexually fromroot cuttings at the above-noted location, and a test row of 10 plantswas established. Subsequently, larger test plantings have beenestablished with asexually multiplied plants at two locations inArkansas. Additionally, the cultivar has been tested at test plots nearLincolnton, N.C., Watsonville, Calif. and in Guatemala with propagationfrom root cuttings from the Clarksville, Ark. test plot.

The new cultivar has been asexually multiplied annually since 2002 bythe use of root cuttings and by rooting adventitious shoots from rootcuttings. It forms new shoots from adventitious buds on root cuttingsreadily. During all asexual multiplication, the characteristics of theoriginal plant have been maintained and no aberrant phenotypes haveappeared.

Test plantings over a wide geographic area have shown this new cultivarto be adapted to differing soil and climatic conditions. In testing inGuatemala, the reduced chilling requirement was confirmed due to goodperformance in this reduced-chilling environment.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying photographs show typical specimens of the new varietyin color as nearly true as it is reasonably possible to make in a colorillustration of this character.

FIG. 1 is a photograph of primocane and floricane canes of A-2312.

FIG. 2 is a photograph of ripe A-2312 fruit.

FIG. 3 is a photograph of the flower and immature fruit of A-2312.

FIG. 4 is a photograph showing the adaxial side of a primocane leaf.

DETAILED DESCRIPTION OF THE NEW CULTIVAR A-2312

Plants and fruit of this new cultivar differ phenotypically from itsparents. The new cultivar is more productive and has larger fruit andreduced chilling requirement compared to both parents. The new cultivarhas sweeter fruit that has much better flavor and postharvest handlingpotential than either of the parent blackberries. Although blackberries(Rubus subgenus Rubus Watson) are highly heterogeneous and outcrossing,and most clones contain genes from more than one species, the newcultivar and its progenitor lines phenotypically exhibit characterspredominately of the erect eastern United States species, Rubusallegheniensis Porter (highbush blackberry).

Plants of the new cultivar are vigorous and prolific and rowestablishment following planting is rapid. Both primocanes andfloricanes are erect in growth habit. The canes can be trained to aself-supporting hedgerow although it is beneficial to use a trellis withsupporting wires to prevent canes from falling over due to wind or heavyfruit-loads. The plants are thorny. Plants and fruit are moderatelyresistant to anthracnose [Elsinoe veneta (Burkh.) Jenkins], but plantsare susceptible to orange rust [Gymnoconia nitens (Schwein.) F. Kern andH. W. Thurston.]. No screening has been done for resistance to doubleblossom/rosette [Cercosporella rubi (Wint.) Plakidas]

The floricane bloom period of the new cultivar begins on March 31 (10%)and average bloom lasts 12 days.

Floricane fruit of the new cultivar begins ripening on June 9, 3 dayslater than ‘Natchez’ (U.S. Plant Pat. No. 20,891). The average floricanefruiting period is 30-35 days.

Fruit yields of the new cultivar are on average 4.4 kg (9.7 lb/plant),comparable to that of ‘Natchez’, in West-Central Arkansas.

The fruit is elongated conical to blocky, bright glossy black in color,and very attractive. The floricane fruit is large (7-10 g) and 1.0 glarger than ‘Natchez’. Floricane fruit size of the new cultivar ismaintained well throughout the entire harvest season. The new cultivarexhibits excellent fruit fertility with full drupelet set. The fruit isfirm at maturity, comparable to that of ‘Natchez’. Storage potential offresh fruit of the new cultivar is comparable to that of ‘Ouachita’(U.S. Plant Pat. No. 17,162) and ‘Natchez’ and exceeds that of‘Prime-Jan’ (U.S. Plant Pat. No. 15,788) cultivars.

The fresh fruit rates very good in flavor, comparable to ‘Ouachita’ and‘Natchez’ cultivars. The flavor is very sweet and mildly acidic, with adistinct blackberry aroma. The soluble solids concentration averages11.9% on shiny black fruit, higher than ‘Natchez’ (9.5%) and ‘Ouachita’(10.4%).

Floricane fruit and flower clusters are medium-large, cymose, and aremostly borne on the periphery of the plant canopy, providing easy accessto harvest. Flower fertility is high and clusters are well filled.

The following is a detailed description of the botanical and pomologicalcharacteristics of the subject blackberry. Color data are presented inThe Royal Horticultural Society Colour Chart (1986 2^(nd) edition)designations. Where dimensions, sizes, colors, and other characteristicsare given, it is to be understood that such characteristics areapproximations of averages set forth as accurately as practicable.

Plants used for botanical data were three years old and grown on a finesandy loam soil with trickle irrigation near Clarksville, Ark. Theplants were fertilized near budbreak (late March on average) withcomplete or nitrogen fertilizer, and had an additional nitrogenfertilizer application in early July. Primocanes were tipped atapproximately 45 inches, and grown in a hedgerow training system. Weedswere controlled with pre- and post-emergence herbicides supplementedwith mechanical weed control activities. A single application of liquidlime sulfur was applied to the plants at budbreak, but no otherfungicides were used. The descriptions reported herein are fromspecimens grown near Clarksville, Ark. unless otherwise noted.

-   Plant:    -   -   Size.—Plants are grown in a hedgerow and primocanes tipped            at approx. 45-55 inches; plants in this system then range in            size from approx. 45-55 inches tall and 36-40 inches wide.        -   Growth habit.—Moderate vigor, canes erect; suckers from            crown and roots.        -   Growth rate.—Primocanes 1^(st) emergence is March 24 and            primocanes reach tipping height (107 cm) on May 31.        -   Productivity.—        -   Floricane.—4.4 kg (9.7 lb/plant), comparable to ‘Natchez’            (U.S. Plant Pat. No. 20,891).        -   Cold hardiness.—Hardy to 2° F. (−16.6° C.) comparable to            ‘Natchez’. The low temperature of 2° F. was the lowest the            cultivar has been exposed to and fruited successfully after            this exposure.        -   Chilling requirement.—Estimated to be 200-300 hours below            45° F. (7.2° C.), lower than that of ‘Ouachita’ (400-500            hours).-   Canes: Thorny, erect.    -   -   Floricane (dormant or winter cane).—        -   Cane diameter.—Base 1.73 cm; midpoint 1.10 cm; terminal 0.71            cm.        -   Internode length.—Base 4.19 cm; midpoint 8.97 cm; terminal            5.39 cm.        -   Floricane color.—Base mostly Green Group (146C) with some            Green-Red Group (178A); midpoint Green Group (146C) with            some Green-Orange Group (166A); terminus Yellow-Green Group            (146B) with some Green-Orange Group (176A).        -   Thorn-density (per 30 cm of cane length).—Base 39.8;            midpoint 28.8; terminus 30.3.        -   Thorn length (from tip of thorn to bottom of thorn            base).—5.0 mm, with non-curved thorn.        -   Primocane (current-season cane).—        -   Cane diameter.—Base 1.85 cm; midpoint 1.01 cm; terminal 0.48            cm.        -   Internode length.—Base 6.58 cm; midpoint 4.72 cm; terminal            7.19 cm.        -   Primocane color.—Base Yellow-Green Group (145A) with some            Red-Purple Group (60A); midpoint Yellow-Green Group (145A)            with some Red-Purple Group (60A); terminus Green Group            (143C) and Red-Purple Group (60A).        -   Thorn density (per 30 cm of cane length).—Base 35.5;            midpoint 47.5; terminus 30.5.        -   Thorn length (from tip of thorn to bottom of thorn            base).—4.5 mm, with non-curved thorns.        -   Date of primocane emergence.—May 24.        -   Disease resistance.—Moderate resistant to anthracnose, and            plants susceptible to orange rust. No screening has been            done for resistance to double blossom/rosette.-   Foliage:    -   -   Primocane.—        -   Leaves.—Large; mature compound leaf width 29.09 cm; length            17.65 cm.        -   Leaflet.—Width 9.78 cm; length 13.16 cm; shape round with            acuminate apex and rounded very slightly cordate base;            margin doubly serrated, serration teeth length 0.21 cm and            width 0.22 cm; pubescence is very light on abaxial and            adaxial surfaces; number of leaflets per compound leaf 5.        -   Color.—Base abaxial Green Group (137C); adaxial Green Group            (135B); midpoint abaxial Green Group (138A); adaxial Green            Group (132B); terminal abaxial Yellow-Green Group (147B);            adaxial Green Group (137A).        -   Petioles.—Length: 7.41 cm; color: Red-Purple Group (60A)            over Yellow-Green Group (144A); texture smooth.        -   Petiolules.—Length: 1.83 cm; color: Red-Purple Group (60A)            over Yellow-Green Group (144A); texture smooth.        -   Stipules.—Length: 1.15 cm; width: 0.09 cm; texture smooth.        -   Floricane.—        -   Leaves.—Large; mature compound leaf width 20.82 cm; length            15.36 cm.        -   Leaflet.—Width 6.43 cm; length 8.13 cm; shape ovate to round            with acuminate apex and rounded base; margin doubly            serrated, with serration teeth length 0.27 cm and width at            base 0.34 cm; pubescence is present moderately on the            abaxial side very lightly on the adaxial side. Number of            leaflets per compound leaf ranges from 3 to 5.        -   Color.—Base abaxial Green Group (138A); adaxial Green Group            (137A); midpoint abaxial Green Group (137C); adaxial Green            Group (137A); terminal abaxial Green Group (137B); adaxial            Green Group (137A).        -   Petioles.—Length 4.52 cm; color: Green Group (143A); texture            smooth.        -   Petiolules.—Length 1.17 cm; color: Yellow-Green Group            (144A); texture smooth.        -   Stipules.—Length 0.83 cm; width: 0.14 cm: texture: smooth.-   Flowers:    -   -   Floricane.—        -   Date of bloom.—10% bloom March 31; 50% bloom April 8; last            bloom April 12.        -   Petal color.—White Group (155D) with Purple Group (75D)            blush.        -   Reproductive organs.—Stamens — erect, numerous. Pistils —            numerous. Pollen — normal, fertile, and abundant.        -   Flower diameter.—3.62 cm.        -   Petal size.—Length 2.12 cm; width 1.71 cm.        -   Average number flowers per cluster.—5 to 6.        -   Average number of petals per flower.—5.        -   Number of sepals per flower.—5.        -   Peduncle length.—1.18 cm.        -   Peduncle color.—Yellow-Green Group (144A).        -   Cyme type.—Elongate simple dichasium cyme.        -   Cyme (flower cluster) length.—ave 151.1 mm.-   Fruit:    -   -   Floricane.—        -   Maturity.—Average first ripe date June 9, 3 days after            ‘Natchez’; with a fruiting period of 30-35 days.        -   Size.—Large, average 7-10 g.        -   Diameter of fruit at primary position on            inflorescence.—Equator 2.28 cm; base pole 1.77 cm; terminal            pole 1.15 cm.        -   Diameter of fruit at secondary positions on            inflorescence.—Equator 1.97 cm; base pole 1.54 cm; terminal            pole 1.04 cm.        -   Length (primary fruit).—3.56 cm.        -   Shape.—Elongated conical to blocky.        -   Color.—Black Group (202A).        -   Drupelet size.—0.52 cm.        -   Seed (drupe).—average length 4.0 mm; width 2.3 mm; dry            weight (50 seed weight) 0.2 g; dry color Greyed-Orange            (164B).        -   Soluble solids.—11.9%.        -   pH.—2.77.        -   Acidity.—0.68 g/100 ml expressed as citric acid.        -   Processed quality.—Not evaluated for processing.        -   Uses.—Fresh market use for shipping is the primary market            due to excellent postharvest handling capability, but can            also be used for other fresh market use including local            sales.-   The cultivar: The most distinctive features of the cultivar are    firm, large, sweet fruit with excellent postharvest handling    potential, attractive fruit appearance, very good flavor, excellent    plant health, potential reduced chilling requirement compared to    other University of Arkansas's cultivars, and high yields.

I claim:
 1. A new and distinct cultivar of blackberry plant named‘A-2312,’ substantially as illustrated and described.